Quicker Maths

Mathematical Puzzle

Apply your calculative skills to find out the answer to this maths puzzle.

Every man or woman alive today had 2 parents, 4 grand-parents, 8 great-grand parents, 16 great-great-grand parents, 32 great, great, great grand parents and so on.

Let us take the case of Ram. Two generations ago Ran had 2 x 2 or 2², or 4 ancestors. Three generations ago he had 2 x 2 x 2 or 2³ or 8 ancestors. For generations ago he had 2 x 2 x 2 x 2 or 2⁴ or 16 ancestors.

Assuming that there are 20 years t o a generation, can you tell 400 years back how many ancestors did Ram have?

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The Man at St. Ives

This is one of the oldest riddles in history.  According to few this riddle has been included in the Guiness Book of Records. Though we are not sure about that. But anyways try giving the answer to this ancient riddle!!

How many were going to St. Ives?

“As I was going to St. Ives

I met a man with seven wives.

Each wife had seven sacks,

Each sack had seven cats,

Each cat had seven kits;

Kits, cats, sacks and wives,

How many were going to St. Ives?”

Friends, leave your answer below -

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Teasing Brain Teaser!!

I met Sweety first time in a marriage party in Kolkata. We exchanged our phone numbers and decided to meet each other soon. When she rang up and invited me to her house, she decided to tease me.

This is how she gave me the number of her house on a particular street:

“I live in a long street. Numbered one the one side of my house are the houses one, two, three and so on.  All the numbers on one side of my house add up to exactly the same as all the numbers on the other side of my house. I know Read the rest of this entry »

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The Lily Pond Riddle

In India water lilies grow extremely rapidly. In one pond a lily grew so fast that each day it covered a surface double that which it covered the day before. At the end of the 30^th day it entirely covered the pond, in which it grew. But how long would it take to water lilies of the same size at the outset Read the rest of this entry »

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Ancient Indian Mathematicians and Their Teachings

We are starting a very special series “Teaching of Indian Mathematicians”.

In this special series we will discuss various concepts propounded by Indian mathematicians which are very useful even today.

Formula for cyclic quadrilateral propounded by 9^th Century Indian Mathematician Mahavira

First in this series, I am explaining a very nice concept propounded by Mahavira, a 9th-century Indian mathematician from Gulbarga (South India) who asserted that the square root of a negative number Read the rest of this entry »

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Is 1 a Prime Number?

Friends, in one of the post where I have described ‘Prime’ and ‘Composite’ Numbers, one of the curious visitor have asked me a very logical question. I will quote that question for your reference –
Text from Previous post-

“Prime and Composite : Any integer which is divisible by 1 and itself only is called a prime number.
unquote

quote
N.B.: 1 is not a prime number.”

Question

Could you explaine what is the creteria thar excludes 1 from the list of prime numbers?
a) 1 is integer
b) 1 is divisible by 1 and itself (1)
Since anybody in the past has declared that 1 is not prime number, why we should follow this without thinking and contravene the general rule for prime numbers?
Is 1 as a figure is something which has come from the thin air. It is and always will be an integer. The criteria for 2 are the same – divisible by 1 and itself. And for all prime numbers.
Most probably the 1 is “guilty” because with 1 starts the series on numbers (natural, odd or prime). Suppose 2 was the beginning of the series. Should we ignore 2, because series starts with 2?

Read the rest of this entry »

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Comparison of fractions: Suppose, some fractions are to be arranged in ascending or descending order of magnitude.

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Multiplication of a decimal Fraction by a Power of 10: Rule: Shift the decimal point to the right by as many places of decimal as   is the power of 10.

Multiplication of Decimal fractions:- Rule :- Multiply the given numbers considering them without the  decimal  point. Now, in the product, the decimal point is marked off to obtain as many places of decimal as is the sum of the number of decimal in the given numbers.

Dividing a Decimal fraction By a Counting Number

Rule: - Divide the given number without considering the decimal point  by the given counting   number. Now, in the quotient, put the decimal point to give as many places of decimal as are there in  the dividend.

Read the rest of this entry »

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What is the difference Between Rational and Irrational Numbers?

Rational Numbers: – Every integer and fractions are rational numbers. It can always be denoted as p/q, where p and q are integers and q is not equal to 0.

Thus for example the rationals include {0, 5/2, -18, -4/3, 27/5}. We unually write rational numbers in their lowest terms, for example 8/10 is usually written 4/5. We commonly write rationals in decimal form, so that 1/4 is the same as 0.25, 13/8 = 1.625 and 4/5 = 0.8. Some rationals, however, when written in decimal form don’t stop a few places after the decimal. For example Read the rest of this entry »

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Difference Between Natural Numbers and Whole Numbers

There is a very small difference between natural numbers and whole numbers. It is important to know this because of both the terms are repeatedly used in questions of competitive examinations. Read the rest of this entry »

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